They did not yet know how many properties had been destroyed, but there were reports of damage.

The fire also came close to destroying the Eves Valley sawmill, but some "sterling work" kept that intact, he said.

They had no idea how the fire started, but believed it began outside of the forestry blocks.

A fire investigator was due to arrive this morning.

The Police's Zane Hooper said people who have not been evacuated should make sure they have access to radio or cellphones that have the ability to receive messages and updates through mainstream media.

Anybody who was evacuated from the fire area needed to go to the evacuation centre at St John Anglican Church on Edwards St, and record their details there.

"This is a fast-moving situation," Hooper said.

Police had about a dozen staff working yesterday and overnight going door to door warning of areas being evacuated.

Notices of potential evacuation are in place for top end of Sunrise Valley and Deep Dale Rd in Upper Moutere and Pigeon Valley.

There have been no reports of injury or worse.

If people evacuate and leave their homes it is asked they register with the Civil Defence Centre at St Johns Church, Edwards St in Wakefield and to ring Civil Defence, 03 5437290, to register they have moved and are safe. This is important to ensure everyone is accounted for and safe.

If people feel unsafe or unsure in any way, they are advised to self-evacuate to the Civil Defence Centre.

The Tasman fire has doubled in size overnight. Photo / supplied

Stephen Cox said the Nelson area hasn't seen rain in over a month and with dry conditions the wind is helping to fuel the fire.

Cox said he first heard sirens shortly after 2pm and only a small plume of smoke could be seen. Now there was a "huge ball of smoke".

"[It has been burning] at least two and a half hours ... there was only a small amount of smoke but since then we've had multiple fire engines, multiple police vehicles all hurtling out there.

The fire pictured on Tuesday afternoon. It has since doubled in size overnight. Photo / Tasman-Marlborough Fire Area.

"We haven't had rain here for weeks and weeks and there's quite a strong southwesterly wind helping the blaze."

"There's just a huge ball of smoke and [water] tankers going out there and fire engines going out there."

Due to high temperatures, dry soil and vegetation, fire risk is extreme in the following areas across the country: Northland, Coromandel, Nelson, Marlborough. A total fire ban is in place for these areas.

Fire risk is also high in the following areas and fire restrictions are in place: Auckland, Hawke's Bay, Bay of Plenty, Central North Island, Wairarapa, Southland/Otago and, as of January 29, North Christchurch.

If you are in one of these areas and thinking about lighting a fire, go to www.checkitsalright.nz to check your fire type and, if needed, apply for a fire permit.